Armature



(No Model.)

J. R. JOHNSON.

ARMATURE.

K Patented Sept. l0, 1889.

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UNITED STATES PATENT OFFICE.,

JOSEF R. JOHNSON, OF YONKERS, NEV YORK.

ARMATU RE.

SPECIFICATION forming part of Letters Patent No. 410,592, dated September 10, 1889.

Application filed March 27, 1889.

T0 @ZZ whom it may concern.-

Be it known that I, JOSEF R. JOHNSON, a citizen of Sweden, residing at Yonkers, in the county of lVestchester and State of New York, have invented certain new and useful ImprovementsinArmatures forDynamo-Electric Generators; and I do declare the following to be afull, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

My invention relates to dynamo-electric generators; and its object is to improve the armature, whereby simplicity and ease of construction are attained and all winding with wire is avoided.

The armature I have invented is of the Gramme-ring type, consisting of an annular core of soft iron inclosed in a continuous endless covering of metal, the turns or sections of which are insulated from each other, each turn being connected with a commutator-segment.

My invention consists in the construction and arrangement of parts hereinafter described, and particularly pointed out in the claim.

In the drawings, Figure 1 is a longitudinal section of an armature embodying my invention. Fig. 2 is an end view, partlyin section, of a portion thereof on an enlarged scale; and Fig. 3 is a detail.

A is the armature-shaft, which is preferably slightly enlarged for a portion of its length where the armature is applied. A sleeve B, of insulating material-such as hard rubber or vulcabeston-incloses this portion of the shaft A. Grouped radially around the sleeve B are a number of metallic bars C, preferably of copper, placed side by side lengthwise of the shaft and insulated from each other in any suitable manner. The bars are preferably slightly wedge-shaped in crosssection, so as to form segments of a ring fitting snugly around the sleeve B. At one end each bar is longitudinally notched or recessed at c to receive a tenon d on the end of a met-allic commutator-segment I). A screw d', or

Serial No. 305,031. (No model.)

other suitable fastening, holds them in close electrical contact. The commutator-segments lie side by side and form a cylindrical jacket around one end of the sleeve Il. They are suitably insulated from each other, as usual. The outer ends of the commntator-segments D and the opposite ends of the bar C are chamfered off at d2 and c', respectively, and on the beveled annular face thus formed is laid a washer E, of insulating material. Against this is placed a ring F, which has an inwardly-beveled face corresponding with the chamfer (Z2 or c', and an outward flat face, against which bears a nut A', meshing with a screw-thread a, cut on the shaft at each end of the sleeve B. By turning up the nuts A the beveled rings F are forced against the ends of the commutator-segments D and the bars O, thereby clamping them iirmly in place. A wrapping of insulated wire G around the inner ends of t-he bars C aids in holding these parts from displacement. Other modes of holding the bars upon the armature-shaft may be substituted for the one I have described, if preferred; but I consider the above to be the simplest and best. From each end of each bar O projects a wide thin radial arm C O2, preferably at about right angles to the bar and terminating at about the same distance from the shaft A. On the spool thus formed is wound the armaturecore H, which, as illustrated, consists of a fiat ribbon of sheet-iron in a spiral coil upon the bars O. The several thicknesses are insulated from each other, preferably by facing one side of the ribbon with silk paper. The core is insulated from the bars C and the arms O C2 by suitable insulating material I. Outside of the core II, and extending across between the arms O C2, are placed metallic bars J preferably 0f copper. They are connected to the arms by rivets or solder. The inode of connecting them is shown in Fig'. 2, each arm C2 being bent laterally and united to the bar J, that is riveted to the arm O of the next preceding bar O. The bars C, arms O O2, and bars J therefore constitute a continuous endless metallic wrapping for the core H, each complete turn or section being connected with a segment I) of the commut-ator. An electric current, generated in any IOC) bar J, will pass down the arm C', across the bar O, up the arm O2, to the next bar J, and so on aroundthe core until it comes to a bar Whose commutator-segment is in contact with one of the brushes.

In the spaces between the bars J, I place a filling K, preferably composed of strips of sheet-iron arranged side by side. These augment the eect of the core I-I, since they practically form a part thereof. They are of course insulated from the bars J and arms C O2. I prefer to form a shoulder k near each end of them, and in the shallow grooves thus formed between the shoulders and the slightly-projecting ends of the arms O O2 a Wrapping of insulated Wire L is placed, which serves to firmly bind the parts together. The arms C O2 are made thinner than the bars O, as shown,in order to provide radial spaces between them at each end of the armature, in which air-currents are set up when the armature is revolving, whereby the parts are kept cool. Furthermore, by making the arms wide and thin I prevent the formation in them of eddy-currents of electricity.

'Having thus described my invention, what I claim, and desire to secure by Letters Patent, is*

An armature of the Gramme type, consisting of the shaft A, the series of bars C, having the recesses c and the wide thin radial arms C O2, the bars J, connecting the arms C C2 of adjoining bars C, the core H, the commutator-segments D,having tenons cl, secured in the recesses c, and means for retaining the bars and segments in place upon the shaft, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

JOSEF R. JOHNSON.

Witnesses:

JOHN F. MAGNUsoN, CHARLES M. PETTERSON. 

